AirHint found the following cheapest return flights from Oakland (OAK) to Seoul (ICN) in September 2025 (see full year).

Return flights

23 Sep - 07 Oct	Korean Air
03 Sep - 15 Oct	Korean Air
10 Sep - 24 Sep	Korean Air
02 Sep - 16 Sep	Korean Air
27 Sep - 12 Oct	Korean Air
26 Sep - 05 Oct	Korean Air
24 Sep - 07 Oct	Spirit Airlines
19 Sep - 06 Oct	Korean Air
19 Sep - 27 Sep	Korean Air
07 Sep - 22 Sep	Korean Air
03 Sep - 17 Sep	Korean Air
03 Sep - 18 Sep	Korean Air
04 Sep - 17 Sep	Korean Air
06 Sep - 17 Sep	Korean Air
06 Sep - 18 Sep	Korean Air
08 Sep - 19 Sep	Korean Air
11 Sep - 05 Oct	Korean Air
29 Sep - 28 Oct	Korean Air
26 Sep - 12 Oct	Korean Air
03 Sep - 01 Oct	Korean Air

Also check the deals for one-way flights from Oakland to Seoul in September.

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

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Cheapest return flights from Oakland to Seoul in September from $838

Return flights